Date of Award
2008
Degree Type
Dissertation
Abstract
A more complete understanding of the forcing mechanisms of global climate change requires us to compare/contrast and synthesize paleoclimate information recorded in both kinds of archives. This "synthetic" approach demands a large amount of work, but the results tend to result in major advances in the field. To date this "synthetic" approach is largely limited to the last 2.7 million years (Myr) because very few continuous continental sedimentary records older than 2.7 Myr are available for comparison with the available marine records. This paucity of continental data is unfortunate because the time interval 5-3 million years ago (Ma) has been proposed to be an analogue for future warmer climate scenarios. Chinese loess and red-clay sediments provide a continuous continental paleoclimate archive for the last 8 Myr and thus provide a chance to improve our understanding of climatic full range variability, especially its variability in a warmer climate. However, in comparison with the well-understood loess-paleosol sequence deposited during the interval 2.7-0 Ma, the climatic and sedimentary processes that cause magnetic property variation within the underlying red-clay sediments are far less clear. My dissertation examines enhancement mechanisms of magnetic susceptibility with in the red-clay sequence on the Chinese Loess Plateau (CLP). I conclude that magnetic susceptibility in the red-clay sequence is a valid proxy for precipitation intensity on the CLP, as is the case in the overlying loess-paleosol sequence based on systematic rock magnetic studies. I then examine orbital-scale and tectonic-scale fluctuations within the magnetic susceptibility time series within the red-clay sequence and their link with insolation and tectonics forcing.
Recommended Citation
Nie, Junsheng, "The magnetic susceptibility record of the Chinese red-clay sequence: Enhancement mechanisms, temporal variation, and its relationship to orbital and tectonic forcing" (2008). Open Access Dissertations. Paper 2219.
https://digitalcommons.uri.edu/oa_diss/2219
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